The energetics of water on oxide surfaces by quantum Monte Carlo

TL;DR

This paper demonstrates that quantum Monte Carlo methods can accurately compute the energetics of water on oxide surfaces, overcoming limitations of DFT and high-level quantum chemistry, with results aligning well with experimental data.

Contribution

It introduces diffusion Monte Carlo calculations for oxide surface energies and water adsorption, showing improved accuracy over traditional methods.

Findings

QMC results agree with experimental data

DMC effectively computes oxide surface formation energies

Water adsorption energies on MgO surface are accurately determined

Abstract

Density functional theory (DFT) is widely used in surface science, but gives poor accuracy for oxide surface processes, while high-level quantum chemistry methods are hard to apply without losing basis-set quality. We argue that quantum Monte Carlo techniques allow these difficulties to be overcome, and we present diffusion Monte Carlo results for the formation energy of the MgO(001) surface and the adsorption energy of H$_2$O on this surface, using periodic slab geometry. The results agree well with experiment. We note other oxide surface problems where these techniques could yield immediate progress.